WASHINGTON -- The Nationals know how to build a farm system. It's one of the reasons they find themselves in first place in the National League East.

Of the players on the current Major League roster, five of them -- Bryce Harper, Tyler Moore, Steve Lombardozzi, Eury Perez and Sandy Leon -- were Washington's top prospects to start the season. Here is how the system fared during this season:

Graduated

Harper, Lombardozzi and Moore have played significant roles on the big-league team, while Perez received a September callup. Harper, who was Washington's top prospect entering the year, is now a major player. Only 19, Harper is among the team leaders in home runs and runs scored.

After hitting a combined 62 home runs the previous two years in the Minor Leagues, Moore is a valuable bench player. The right-handed-hitting slugger credits veterans such as Chad Tracy and Mark DeRosa for teaching him how to come off the bench.

The Nationals consider Lombardozzi an everyday player, but he spent most of the season as a reserve. Injuries to Michael Morse and Ian Desmond forced Lombardozzi to often play the outfield and second base.

Perez was arguably the team's best prospect in 2012, hitting a combined .314 with 42 RBIs for the Gulf Coast Nationals, Double-A Harrisburg and Triple-A Syracuse. Ranked fifth among Nationals prospects by MLB.com, he will be used primarily as a pinch-runner this month.

Leon is the third-string catcher and has had two stints in the Major Leagues this season. In 10 big-league games, Leon is 7-for-28 [.250] with two RBIs.

Dropped off

Catcher David Freitas and pitchers Paul Demny and Taylor Jordan started on the preseason list, but fell off for different reasons.

Freitas was traded to the Athletics last month for catcher Kurt Suzuki, while Demny was inconsistent for Double-A Harrisburg, going 6-8 with a 5.36 ERA. Jordan is a year removed from Tommy John surgery, but his fastball is currently clocked as high as 96 mph.

New faces

Leon, Lucas Giolito, Matthew Skole, Daniel Rosenbaum, Nathan Karns and Jason Martinson are new to the list and Leon is the only player who was promoted to the big leagues.

nationals' top prospects

Giolito, who was the team's first-round pick in the 2012 First-Year Draft, had Tommy John surgery recently after pitching two innings for the Gulf Coast Nationals. Skole was recently named Washington's Minor League Player of the Year and right-hander Karns was its Minor League Pitcher of the Year.

Skole hit a combined .292 with 27 home runs and 104 RBIs in 118 games for Class A Hagerstown and Class A Potomac. Karns, 24, was 11-4 with an organizational-best 2.17 ERA in 24 games with Class A Hagerstown and Potomac.

Rising/falling stock

Third baseman Anthony Rendon is Washington's top prospect despite missing a lot of time because of an ankle injury. In fact, manager Davey Johnson was hoping to bring him up to the big leagues this month, but he slumped badly while playing for Harrisburg.

Brian Goodwin went from eighth-best to the third-best prospect in the system. Drafted in the 2011 First Year Player Draft, Goodwin hit a combined .280 with 14 home runs and 52 RBIs for Class A Hagerstown and Double-A Harrisburg.

Top 100 representation

Rendon, Goodwin and pitcher Alex Meyer were selected in the 2011 First-Year Player Draft and are rising fast in the system. Rendon and Goodwin are already moved up to Harrisburg, while Meyer's first year in pro ball was successful, going a combined 10-6 with a 2.86 ERA for Class A Hagerstown and Potomac.